"Think For Yourself, Schmuck!", one of the central dogma/catma of Discordianism.

Similar and related phrases in this context are "Question Authority, Think for Yourself", "Black Sheep are still Sheep", "The Map is not the Territory", "Don't Eat the Menu!", "Do What Thou Wilt Shalt Be The Whole Of The Law--But Remember Nobody Likes an Asshole!", "A Conclusion is Simply where you Stopped Thinking" and of course being forbidden to believe anything that is written.
"You were just doing your job..", that is the lamest excuse ever, don't you have a brain?! TFYS!
by Ein Sofa Uhr October 16, 2009
Get the TFYS mug.
Basiccally standing for "Think for yourself", can be used in a criticizing or encouraging manner.
"You're always listening to them. TFYS, dude."
by Blainster0091 March 1, 2009
Get the TFYS mug.
The Fuck You Say? Used when someone says somehting that generally disgust you, confuses you, or just makes you mad.
Boss: I need this job finished now, you'll have to stay late
Employee: TFYS?

or
Wife: You just need to pack your shit and go!
Husband: TFYS?
by Bevoblood October 13, 2009
Get the TFYS? mug.